I use Collinite No. 476 Super Doublecoat Auto Wax which you can get on Amazon. I tried using the Starbrite Marine Polish with PTFE but never liked how it went on. I don't think anyone waxes their kayak for safety reasons, but to keep ocean/lake grime from building up, I find these work very well, especially the Collinite.
I race, so I wax my boat regularly. It's more a ritual than anything else.