Thanks for the input, I did end up soaking him in my sink yesterday but I took him out after around 15 mins. I used a temp gun and the water temp was 90F when I put him in, but as soon as Noodle touched the water he went rigid with fear (he basically just went stiff and his body would stay in the same shape even when I moved him. I tried gently massaging down his body and tail but no results (then again I think the time he was in the water was shorter than recommended). When the water cooled down I took Noodle out and replaced it once but when I put him in the second time he started trying to climb out so I ended up just taking him out.

Before he peed on me I could feel something hard around his vent area but once he passed the urates that was gone. I've felt around his vent again and everything seems to be soft so I don't think he's impacted or anything. If he still doesn't pass anything for another week or two I'm going to try soaking him again for a longer time.