I have noticed.
Due to some days I sweatmore, and stress i.e I cant be bothered to pull as good and it slips.
If its a cold day I cant get much cock to grip than a warm one as he plays tortoise.
Would acvise you get those gloves, like golf goves I have heard mentioned here time to time as they seem to grip great whenever, thought I havent got a pair so I cant tell you my thoughts directly of this method.
Yea some days its hot down here and real sweaty so my grip always slips or isnt that great. Other days I feel like I got this amazing grip and I get a good workout... Depends on the weather alot for me
I'm in the same boat as you guys - some days are better than others. Not sure quite what it is, but it may be the pump I sometimes feel. When I have a slight pump , my head is engorged just a bit, but enough to help with a good grip and thus, a good stretch . I haven't tried the dishwashing gloves yet, may try over the weekend as I get tired of slipping.