@Ian I keep forgetting you are in Texas and I am in Ohio. Was giving that some thought. For what it matters.
The type of stuff we haul in and on aluminum trailers, put on the roads around here in the winter and so forth probably is why Zep A Lume is used a lot around here.
Probably not a lot of use for it down there in Texas.
Figure we salt, calcium and put ash on the roads in the winter. We freeze and thaw constantly, so weeks of high humidity, slushy roads.
We haul coal, coke flux, salt, a lot. We have a lot of dirt roads in a lot of areas full of trees so our dirt is slightly pH challenged in those areas.
Every spring around here our vehicles need to be thoroughly cleaned, and inspected if you want them to last. Every fall most truckers and businesses go thru some kind of get ready for winter ritual. Cause to tell the truth a vehicle around here January thru March hardly gets touched unless something is broke or it is so dirty the driver or customer gets dirty getting in it. So three months of torture and neglect every year.
The coal industry used to be booming in this area, especially in our connecting states of PA and WVA
They even used to crush 2nd rate Coal and throw it on back roads for gravel. Coal dust is extremely hard on aluminum.
So kinda makes sense why It is almost a household word around here and you never heard of it.
I am sure you can find a good aluminum etching product in a smaller container.
Pretty much any thing that contains acetic acid, or citric acid will work. You could use vinegar or lemon juice, it's not concentrated so you want to leave it sit a while and go over it a couple times. Zep is just faster and more agressive.