Two short suggestions. But first I digress....
I am sure you are aware that synthetic hair is a "plastic" usually composed of polyester, acrylic or polyvinyl, or, some combination. The good news is that synthetic hair today is far superior to what was available years past. Legacy synthetic hair tended to have a poor texture (it did not feel right), it did not look real (like human hair), it was susceptible to frizzing, and it could melt if one used a hair dryer. That has all changed. Modern synthetic hair feels very silky and smooth (most people would likely prefer the "feel" of synthetic hair compared to human hair assuming a preference for the silky smooth feel). Frizzing is almost nonexistent. Heat does not affect the hair.....I have tested synthetic hair using a hairdryer, at the high setting, held one inch from the hair for an extended period without any issues. The exit temperature of the air from the nozzle was over 225F measured with a digital cooking thermometer.
I mentioned on another thread that I started wearing 11 years ago. I became interested in hair ventilation about a year later when I read on a forum that one could with basic ventilation knowledge and experience easily add hair to a lace hairpiece when shedding started to become noticeable, particularly at the hairline. I ordered some basic supplies and tried ventilation. Slow and inconsistent at first, but, I got better with time and practice. Even a few hairs added to areas experiencing shedding can produce very dramatic results. About 5 years ago I became interested in synthetic hair. I saw an example of a hairpiece made with synthetic hair by a member of another forum (Dave, I think,.....some of you no doubt know who I am referencing). I exchanged a few messages with Dave who told me that of all of his pieces that he had made from scratch the synthetic hairpiece was his favorite. I ordered an assortment (different colors) of women's heat resistant synthetic extensions from China to use for my experiments. The hair length of the extensions ranged from 18" to 24". Very long. I would cut off perhaps 50 hairs at a time from the clips that hold the hair in place to use while ventilating. Tangling issues right from the start. The hair often tangled while still attached to the clips and the cut hairs used during the ventilation process would also often tangle making ventilation a real pain. Too much static electricity magnified by the fact that I live in the desert SW (USA) in a very low humidity environment.
I decided to try applying a "leave in" type conditioner on the hair hoping that it would eliminate the static charge and also facilitate the detangling process while ventilating . It worked. I used a 50/50 combination of Infusion 23 (well know product that has been around for decades) and distilled water. I mixed the solution in a spray bottle for easy application.
That was a long introduction getting to my suggestions for you should you have tangling issues with the grey hair.......
Infusion 23 works well. But so does any good quality conditioner. I suspect a detangling product might also work. However, my experience with detangling sprays has never been good. I have asked cosmetologists to recommend a good detangling product. Nothing satisfactory to date. If you do not have a product like Infusion 23 you could easily mix a solution conditioner and water, or, even use full strength conditioner. Since I do not know how you maintain your piece......do you shampoo and dry while wearing or while detached? If you have tangles while wearing you can try applying a solution of conditioner/water to the ends of the hair. Perhaps the last 6" followed by followed by some gentle combing with a wide tooth comb. Or just use your fingers to separate the hair. You may have to rinse out the solution depending on the mixture strength if it looks and feels ok to you. Infusion 23 can remain in place. I always thought Infusion 23 at full strength was too heavy. Your experience may be different. This process is simple and quick, UNLESS you have a real rats ness!
The second suggestion is to use an ionic hairdryer assuming that you use a hairdryer. Ionic dryers in theory produce ions that reduce the size of a water molecule thus accelerating the drying process which should reduce tangling and frizzing. I have used ionic dryers for about 2 years. A positive experience but nothing dramatic. Again, your results might vary.
