Make sure it isn't the brand of solution that contains H2O2.

I have one 6oz tube of medical gel and I don't 'declare' it; I just put it alone in one of the round tubs Rx label up and put it on the x-ray belt with a foot of space on either side. It usually comes out the other side without any comment to me (they always stop the belt for ~5 seconds to look at it). Sometimes they will ask whose it is and ask to 'test' it, but that is less than 20% of the time.