Aldi are selling 5kg bags for £2.99 , much cheaper than Sainsburys and Tesco at £5. Tried some last night and they worked fine! Also remember the coals remain hot for a long time so don’t put them in the bin too soon!! Leave them over night to cool and either dig them into garden or dispose of them in the bin then. The same applies to the disposable BBQ’s they also remain hot for a surprisingly long time!