So I went to the local motor factors to pick up air filter and some MAF cleaner as mine is a little dirty. He told me that brake cleaner is exactly the same stuff and will do the job for a fraction of the cost. Is there any truth in this? Seems like he was just selling me that because he didn’t have any MAF cleaner there 

Some brake cleaners may be too aggressive on the delicate elctronics, also the pressure it fires out the liquid from the can may be an issue depending on brand. The safe route is to use isopropyl alcohol, it is available in places like maplin, also available on that populsr online auction site as well.

By most accounts, an electrical contact cleaner (switch cleaner) spray is safe to use because it doesn't leave behind residue like a brake cleaner or carb cleaner spray can.