I've had success using the bicarbonate of soda + hot water method to clean oven trays in the past (e.g. https://www.ovenpride.com/blog/cleaning/a-guide-to-cleaning-oven-trays/#:~:text=Combine%20boiling%20water%20with%20a,up%20the%20burnt%2Don%20bits), but I've got a large (~14" diameter?) non-stick pizza baking tray that is too large to fit in my sink (or a bucket etc) - any suggestions how I could properly clean it? :)
(before someone suggests putting it in the bath, I don't have! Only a shower tray with a non-pluggable drain)