Hi Fishperch
I am a bit fussy about my bait so I don't care what reaction I get when I hand the bait back, that said we are talking about buying a product that could potentially be a minefield of dubious bacteria and nasties!
I did put an article on here about “Maggots and how to get the best from them”, it must be on this site somewhere, there is a section about cleaning and preparing old bait that you might find interesting.
I get my Maggots and casters from Colney Tackle in London Colney Nr St Albans and Harefield Tackle.
Both supply superb bait, fresh, clean and you get a full pint from both, can’t remember the prices but to be fair quality can sometimes be a little extra.
I tend to keep away from shops I don’t know but in the main, if the shop has a large clientele of Match anglers, you can usually expect the bait to be of decent quality!
Tight lines