I cut mine back (so no real seals per se), but when I use seals I just use the same baby shampoo / water mix that we use on masks and for helping people get in their wetsuits.You guys talk your suit's seals before each dive? I'm thinking to use a soap water mix spray bottle instead.
I forget to 90% of the time, but I think it helps to talc the inside of the suit. Helps the undersuit slide in better.