Where in California are you--heat all by itself doesn't necessarily mean you need to post every three days. When I was in Sacramento--which is fairly humid because of all the rivers--if it got hot it also tended to be more humid. In Southern California--LA for me--that's basically desert and when it gets hot often the humidity was low and I could leave ears up 3 or 4 days. Sometimes even 5 days. There are some places where the heat and humidity are practically identical, 85 degrees and 90 % humidity and you are changing posts every 2 days. In Portland, Oregon (that's the left hand one) humdity is not often an issue but for about seven months of the water is--just plain old rain. We learn all the ways to keep posts dry and still be able to keep the posts dry (ask me about the guy who used a pair of condoms--yes, really--he said it worked better than anything else he'd ever tried.
Oh yes, and try to avoid taking his posts down when you can't stick around long enough to put them back up right a way.
If you don't have Uni-Solve you can use any kind of oil that will act as a mess but effective adhesive release agent. I've use various kind of cooking oil--Olive oil, Wesson oil, mineral oil (baby oil works but I don't use it because they perfume it and it stinks) I even resorted to a pat of butter stolen at dinner by a breeder and I who were trying to repost a puppy.
The trick with oils is to have a small container of it and keep dipping your fingers in it and rubbing them along the edges of the tape--as the edges loosen you can start using q-tips to get further under the tape but I just keep goopin more oil onto the tape and freeing it as it loosens.
If you are using oil of any kind you do need to make sure you have all the oil off before you repost or the new tape won't stick. I use a cup of water with a few drops of the old regular Dawn detergent--it's an excellent degreaser and not toxic--they use it to degrease waterfowl who have been oil soaked in an oil spill.
And the best news of all is that when you finish posting ears, all that hair than came out will grow back--it always does.
dobebug--now I have no excuse not to go mow some lawns.