It's like the cosmolene we used to pack guns in as a preservative.
Remove it completely and use something like Hornady spray lube and do not overdo it.
Anything much heavier and you run the risk of dimpling and otherwise damaging brass when resizing.
Usually I just throw my brass in a ziploc bag, spray it pretty thoroughly and let it air dry completely before starting.
You have to let it dry thoroughly though or it has zero lubricity and cases can easily get stuck as a result while wet.
RCBS liquid is "slicker" but it's also messy and it is pretty thick so if you get any excess particularly in the neck/shoulder area it can easily damage them.
Other guys like to use the various wax prep's this is my preferred way to go.