Swims always had good to very good results with pressurised steam cleaning and then autoclaving(sterilizing)

I had a couple screwups that refused to come clean. Naoh solution got them clean even though it took a few weeks and solution changes. It does eat a small amount of the glass, but screw having to buy new glass if at all possible.

Depending on how readily avail your stocks of h3p03 are i find that is the best cleaner i have come across, you dont need a great deal and if done straight away it makes the job alot easier.
                       8ball