i had some success on liquid ,used it for about 15 months.Ive had better results on foam though and its much better to apply.
with the liquid i had a dropper and just applied it directly through that to the scalp and tilted my head one way then another to let it run all over
with the foam depending on whether im being lazy or not i either part my hair several times and apply along the line or just dab it all over ,applying directly with the nozzle against the scalp.