Making a udwc unit with 2" rubber grometts need help

I have 2" PVC going from 5 gallon bucket to 5 gallon bucket. They are being attached by 2" PVC. I have cut the holes in the buckets and I can fit the grommets in but when I put dish soap on both the grommet and the PVC tube I have a hell of a time getting them in all the way. Is there a trick to getting this done more easily?

Honestly I wouldn't use grommets on holes that size. Look into some called a uniseal. I just ordered some the other day, high quality. Just google the original uniseal, loom for a site with the name Aussie in it, they have the best prices I've found

That's actually what I'm using. Its a grommet to me. I called them today and they sad to put dish soap on the seal and the PVC and also taper the ends to allow for a more smooth insertion. Still hard though.

Won't leak though.