In reply to Dave Ing:
> (In reply to odox)
> [...]
>
> A few litres of water soon cools them down enough for the cool ash to be spread at the base of desirable plants as a fertiliser. May not be as good with paraffin-impregnated / instant light briquettes
Disposable BBQs do a lot of cumulative damage if they are sat directly on the ground, regardless of the fire risk