I just beat this one this morning, and the good news is I did it without bombs at all, so I should be able to replicate it all three times.
I used the Octobrush, which is handy to not have to aim when things get crazy and to get around for flanks quickly, especially against Brella users. It also takes out wave 2 instantly, which gives you some breathing room. A lot of it is memorizing where the Octolings jump in and attacking them immediately. I actually used the Bubble Blower, which bought me some extra time, and the Inkjet, which let me pick off a lot of the Octolings easily (they don't evade much in this mode).