I've been looking for the same thing for few months
Obviously KBT Pure/Race keycaps are not grip at all.
Sadly I don't have any connections from Korea. Those orange rubber looks awesome.
I post an wanted ad in my local area few months ago, offer $20.00 only for the k60 rubber keys, but no reply.
I like the texture of the CM rapidfire wasd keys (brought from FusRoDah) and KBC pbt.
I also try put a rubber sticker on keycaps. Eventually, it moves and becomes sticky. But put on a pbt with super glue is better.
Recently using WASD textured keycaps. I guess they could last longer.
Let's keep looking for our grippy cherry mx keycaps
I know what you mean the coating like, on logitech G510 keyborad. But I don't think it's available ...