It's going to depend on what you are using for fuel but I never get more than a manageable amount of ash but I usually only burn about five pounds or so.
As for the lid I remove the bung holes ( they have a rubber gasket on them) and add it to the blazing fire propped up with some of the burning timber. Others use chemical strippers, weed burners etc.
A few pictures..
Notice I have holes in the ash pan so that it helps to breath and has a complete burn...
In the drum...
Slappin that bass like some delerious funky preist!!!
UDS, Half Pint (Mini UDS), Weber, ProQ 20, Kegrilla
*250 gallon cooker- 'The Meat Beast!!'*
British BBQ Championships
Grand Champion 2008
British BBQ Society - Southern Championship
Grand Champions 2009