We had a coder in our company and she wrote me a script which chooses the most smalles objects and helpers.
That way I can remove nuts and bolts easily.
Also, if I have a super mega heavy object, which doesnt need to be so detailed, I usually add a MultiRes-mod.
With that I remove ~50% vertices, maybe even more if the object stays ok. (sometimes need to add a Normal-mod too after it).
After removing I convert to poly so the modifiers are removed.