https://www.campingworld.com/protect-all-fiberglass-oxidation-remover-and-color-restorer-64-oz.-16030.html?gclid=CjwKCAjw9vn4BRBaEiwAh0muDHuym63KTkGaEscdZwpX6qEj5oY51XD48W-QINa0FpuucpV98nzR3hoCO7cQAvD_BwE&gclsrc=aw.ds
This stuff in the much smaller bottle will hook you up for ridding the chalk. You don’t even need a buffer but you can use one if you want. I’ve used it both ways.
Also 3m makes some stuff in both blue & green labels that’s fantastic as well.
Note: Use a good quality ‘sealant’ after any of the above products or else you’ll be doing it again in short order (especially if it’s hot weather time).
I like to use Turtle Wax Liquid Ice as a sealant. Been using it for years on my gelcoat boats, trailers, & motor home.