We place a sheet over the engine compartment. Then we remove the chunks in as large a section as posible. Then we use a wet-dry vacuum cleaner with a angular straight end to scrape down the remaining material. A sharp puddy knife persuades the tougher spots.
We also use the 3M 08090 spray adhesive in the technique used above. The benefit to the 08090 over many other good adhesives is the wand type spray pattern which allows for even coverage, both sides.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician