Cant get engine degreaser? Have a look in ACE hardware in Megamall.
If you want to clean engine blocks, heads, etc AFTER disassembly but cant find anything strong enough, just use oven cleaner. Where to get it? I dont know as I cant seem to find anything Im looking for in Malaysia. bleh. Oven cleaner shares a lot in common with engine degreaser (both come in cans like spray paint) but often at lower price. Here? Cant say.
Edit: not sure of effects on alum parts! Any cleaner is likely to be bad for bearings btw.
A proper job would be to have the part "tanked" in a large vat of heated chemicals. But if you are doing yourself (nothing wrong with that!) be sure to check all the passages too... they make special brushes for this that can be helpful on stubborn passages.
Where to get brushes? I dont know. If you had a gun store that would be one source.
Rinse well with water... then dry quickly with compressed air. The oily coating method from Cloudz is appealing but paint may not stick if you plan to paint.
Acetone for sealing surfaces works well.
If I misunderstood the Q, then nevermind.