I was running around looking for Slagga or good slag SMG then realized I had a great Mali slag sniper that I could use as a perfect slagging sidearm! After picking up some additional excellent gear for the job everything kinda fell into place and at last I was able to beat the loader dome with Axton 
I didnāt even have to go and get the corrosive hail either! I only got last 10 minutes around of the action but itās the hardest bit for sure.
Thatās a lot more skills than me. You like playing it hard donāt you!
Thumbās up 
for non-conventional slag weapon. I did it way more defensive. Hiding in the container most of the time.
Actually I am thinking now a Mali sniper pretty much could be the go to slag weapon for Axton and Sal as these guys can receive NO bonus anywhere to boost slag chance (maybe Zero too but he would be great with slag pistols too).
The Cher-Amie Moxi sniper itās not that great (only got a 5 shot mag), but I got a slag one actually I am thinking this could be an EXCELLENT weapon for Sal, as I spec with his boosted mag size skill.