Cashiers can still Disc Dump things... sort of. It's not the proper way to do it though.
Type in a random 8 digit number. It will come up "GEN HOST ERROR". Go Unknown Item -> and from there it will do all the departments to charge it to, though you'll have to be more specific with what you're charging the item off as compared to a Dissection Dump (for example, SVR only needs to charge to PERISHABLES, whereas this method requires PERISHABLES -> FRESH MILK/YOGHURT/FROZEN GOODS/ETC...).
I don't recommend doing this though, as it shows up in a Not On File report (which prints after the transaction is finalised, and I believe that you should be handing to your supervisor). It would look suss with a random PLU and you could definately get in trouble for messing with that. I did it once, but that was because I had no idea how to manually enter weighed produce. I was supervising when I did that though, so it's okay.
I do recommend you use this method however if you scan an item which says "GEN HOST ERROR". Instead of the supervisor doing it generally, you can charge it specifically to the proper department and product (for example - PRODUCE EACH, or FRESH MILK) and it will be recorded with the barcode number that caused the error. Whereas a Disc Dump does not do this.
Just my two cents.
EDIT: You don't need any super privileges/approval whatsoever if you do the GEN HOST ERROR way, if you haven't guessed