Here are a few things I've discovered lately.

I often use those arrow magnets to hold steel parts together and on my tig table to position aluminum parts. What I have noticed is that you cannot have magnets around the weld area especially when tigging aluminum with pulse. It just will not allow the torch to strike an arc with any magnets near the weld area. I have not had much of a problem with DC and magnets.

Now as far as aluminum cleaners go, I recommend not getting them. I have tried several aluminum oxide removers and all have not worked nearly as well as a good stainless brush and acetone. I have had problems with aluminum cleaners with residue left. When using these cleaners, you really have to make sure that you get every bit of them off the aluminum or you will get contamination. Plus that stuff is really expensive. Like $25 for a small bottle. Best bet is a gallon of Acetone for $17 and a good stainless steel brush or wheel. I have found that acetone really is the best oxide remover and will also remove most any other contamination present.