Generally I use whatever sealant/Wax I'm using on the rest of the car or wheels too. If you're asking for what sealant/wax to buy then there's a ridiculous amount of options. I'm currently using natty blue paste wax which is fine but does not last long enough for me and generally doesn't last long on wheels at all. I have tried the spray on autoglym stuff and that wasn't up to much so I'd give that a swerve. I'm toying with switching to the gtechniq range or wolfs chemicals hard body sealant for my body work and will probably whack that on my wheels too. Seems expensive but the reviews all seem to be pretty good for them both.