I use windows cleaning fluid (e.g windex) when I want to pimp up a board before selling it.

Avoid any aggressive product (car polish, alcohol, solvents), as it may dissolve the varnish/paint on some brands, unlike surfboard hotcoats.

Mine get used, waxed pads, dirty and shoved in the garage for next time

For grip...I've always put a layer of wax on deck pads for many years ...ever since I started sup surfing. Maybe coming from prone surfing beforehand influences this choice but some deck pads are not that grippy IMHO. Can't beat a thin layer of wax just where you normally stand. Funny as I only saw last year that Kelly Slater waxes his foot pads on his surfboards...maybe he is copying me