My male pied had a rough first shed with me. I had him in a tank and humidity was way off, so after he started shedding I realized it was off and covered the top and misted but it didn't really help, I guess the humidity was all over the place so it wasn't working. I did some baths and that got off pretty much all of the last 2/3rds of his body but his head and neck still had some. I've gotten it off now pretty much with tubs and I've just poured some water on the towel to bump up the humidity and put in a fake suction cup vine that he crawls in and out of (also works as a decent hide since he's still smaller).

I'd also consider switching his tub or tub location, maybe the shelf he's on has more of a gap than others.