I use the gel ear cups on my radio pelators at work, and they are a PIA when I have to replace them. I tried to put a backup set on my wife's shooting muffs and could not get them on, but it was about 10 F out and I just thought it was the cold.
This is my technique also. I am on my fourth or fifth set of the gels, seems like I tear them and have the gel leaking out about once a year. But I wear them for 7-8 hours a day and the gel ear cups are well worth the money.
The gels are well worth the money. I've been wearing aviation headsets from 1 or 2 up to 12+ hours a day for about 14 years, and had the gel earseals almost the entire time. When I found out I could get them for my Peltors, I almost started dancing. The aviation models are pretty durable, but I also take care of them better than my shooting headsets. The first pairs lasted about 5 years on the flying cups, and 2-3 years on my shooters. Makes all the difference on the airplane or the range for 6-8 hours on average.