I believe without using sappers it becomes a long drawn out affair that requires even more consumes as mentioned. Guilds killing it back in vanilla was using GNPP and stacking dispelling classes (Druid, Paladins and Shamans) as well as having everyone in NR gear. I believe they would have small teams designated to each part of the room to work together to DPS as many blobs down before they reached the middle then have mages and locks AoE.
I think this will be a boss that will require consumables even when you have Naxx on farm but I could be wrong.
Personally I don’t bother using any caster consumables when it comes to Viscidus, it’s not a DPS race so it’s pointless. With enough people using 1 sapper each it should be enough, pre pot GNPP and use a few Elixir of poison resistance (Only when dispels are slack).