I recently bought a Skwoosh pad from someone on the board. I have tailbone issues. I also have a Wally world cushion. I tried both and found neither of them, separately, did anything for MY issue. However, together, I can now ride for a much longer time, over 4th of July put 980 miles on her in 4 days.
I put the Skwoosh pad INSIDE the wally world cushion it fits really well. Egg crate side of the Wally world up, gel pad under the rubber insert of the wally world cushion, then cut a tail bone relief in the wally world rubber part.
My tailbone still got sore but could ride through a tank of gas before it got really uncomfortable and had to get off and stretch but at that point I needed gas anyway.