*Sorry for the long paragraph but it's worth reading if you know/ride with brakes*
So I've made a thing here before talking about the Odssey Slim By Four brake pads in clear, they seemed to work for about a week then after, I had major problems with them and eventually gave up on riding brakes cause I was having to clean every night and sand them down to get new rubber. A couple of days ago I was riding and ate shit going way too fast pulling a hop manny, really fucked my hand up cause I was stupid and didn't let go of my bike. So today I had, had enough and went to the bike shop and bought some Kool Stop Supra 2 brake pads. I was recommended them by a friend to be "the best pads" and "would stop me on a dime" well they didn't, and I'm a bit angry to be honest. The only thing they do is make a loud ass banshee like sound, I know how brakes work and am not being stupid, yes i know you have to let them wear in a bit and seed to your rim, and yes I know how to setup brakes properly. Another problem I might have is that my rim is painted which means the pads can't really catch like theyre supposed to, Ive sanded down the rim enough so that you can see the metal. Soon I'm going to buy a electric sander and finish off the job so the rim walls are fully raw. So after all this reading my main question is, how tf am I going to get my brakes to actually stop me and work like my friends do cause mine aren't catching, theyre just sliding and sorta catching. Thanks for the help feedback of any sorts is very helpful and especially if you ride with these pads.