[cm2187]

For an unmanaged object you can use Dispose/using, but for a managed object, I am not aware of any way to explicitly delete it from memory once it has been dereferenced other than calling gc.collect.

For unmanaged object I am surprised it would keep it in memory for a bit since it is also the mean by which you release any lock on a file or a connection. If you don't execute it straight away, you potentially create bugs.

I think the reason why Microsoft was telling people not to call gc.collect is that it interferes with the optimisations and heuristics that the garbage collector maintains to optimise when to do a GC. But I must say I didn't notice any abnormal behaviour when I did. But I would only do if I absolutely have to.