I've always used this stuff.
https://www.turtlewax.com/images/default-source/product-images-revised-2014/t49-f21-tire-foam-and-shine.png?sfvrsn=2[img]
Spray it on let it sit while I vacuum/clean interior then use a curved sponge like this to wipe it down.
[img]http://images.oreillyauto.com/parts/img/large/eag/5010602.jpg
I worked at foam manufacturing plant where we made those :roflmao: had tons of lil sampler bags at home