Advice

Ok, so I can't seem to take a decent pic, so I get advice might be hard.

I can't get my bong clean. for reference it has an ice catcher

so, just above where the water would sit, I get marks which I'm guessing are residue, that I can't seem to clean.

I use isopropyl 91% and I use epsom salt. I swirl it, shake it, etc. it won't sift and with the ice catcher, I can't seem to get a brush in to try and scrub.

any advice.