I worked Custodial and absolutely LOVED it. I'm planning on doing a PI next, but if I were to do ICP again I would totally do Custodial in the blink of an eye.
I won't lie, there is work involved. I like keeping busy, so I actually liked the cleaning, but I know some of my co-workers were less enthused. Yes, there are trash runs and bussing tables, restrooms and code Vs; but once you get through the first week it becomes second nature and you hardly even think about doing it.

Besides, the "horror" stories you hear about Custodial are a lot more amusing when you're the one involved. You'll see some crazy things in restrooms and on streets, but through all the weird things I've dealt with, I always look back and laugh.
But what I really loved about Custodial was the freedom and the guest interaction. There is SO much guest interaction- I spent so much of my time just pin trading, giving directions, pre-parade games, making water mickeys, learning about where people came from and why they were here. I met a lot of really interesting people, and made a lot of people smile. I can't speak for anyone else, but seeing people smile and making a kid light up over something as small as asking for their autograph, or giving them a sticker is absolutely heartwarming.
If you have any specific questions about Custodial, feel free to ask here or PM me. I was really nervous when I applied, and had to know every detail about the role first, so I totally understand that!
Good Luck!