Australia's Science Forum

Oxalic acid ONE OF THE BEST, my first port of call

Napisan ingredients:- 'disodium carbonate, compound with hydrogen peroxide (2:3) ≥10 - ≤30 15630-89-4
Reaction product of Benzenesulfonic acid, 4-C10-13-sec-alkyl derivs. and
Benzenesulfonic acid, 4-methyl- and sodium hydroxide' from the SDS.
It may need a risk assessment for your lab techs, but it is ok down the sink.

I use 36% HCl on glassware. Obviously, I use the fume cupboard and PPE. Leave to soak overnight and voila! Usually gets anything off. I return the HCl to a stock bottle for for future use - it lasts for ages.

I use 10% HCl, soak for a few days and off you go.