I started it earlier this year from like 25th of october so i'm 17 days strong right now, but how some people already said it's not a big achivement tbh, not doing PMO is a self control thing. Some people can't control this for like 2 days, let alone 30, but again most of the people doing this challenge are doing it for the meme mostly, not actually for their own benefit, most of them will prob relapse on 1st of december.
Also yes, porn is not good in general, i mean you could watch it now and then, but don't masturbate to it or over use it it will change your mentality.