Yep, all you have to do is to mod game with this small file: NEXUSMODS[www.nexusmods.com].
This won't block the achievement. I'm almost sure you can't get banned for this (this is single player game).

Every throw in dice-poker after installing this mod will count as five-of-a-kind.
I do not recommend this to get rich fast - but I recommend this for all of you, who want 100% achieve done satisfaction, and don't want to waste time with such nonsense. (btw. I saw a lot of posts on forums when ppl playing Witcher 2, couldn't get poker achievement but they were past madman one.
I was the one with such problem as well. "Madman? No problem! Poker!? emmm....give me like 80h to do this." ridiculous)

Of course you can call this cheating, but it's not. It's single player game, prepared for soft modding (as you can see in the launcher), and please take to consideration all the ppl who don't have time or will to roll the dice for the whole ♥♥♥♥♥♥♥ day to get this achievement. I know, da feels of getting it is propably enormusly wonderful, but be realistic - it's a crap of a achievement to waste such amount of time.

Thank you CD PROJEKT RED for great game, but that achievement...is a cancer. >_>