Round one listed some packs of free VST plugins with the added purpose of ease of availability and installation so you don't have to worry as much about missing plugins when loading old tracks into your DAW. Today's list includes a few individual oddball plugins that have a similar purpose, but aren't quite the RSTLNE of DSP.
Xfer Records OTT
Basically, you can take any channel of harsh sounds or an individual sample/instrument, drop OTT into the chain, and not worry about how it fits into the mix, because it will simply always be OTT of the mix. After meddling with with the downward and upward compression or not, you can then use it like a DJ boost or kill EQ to cut the high, low and/or mid. Secretly, I'll even use it on the master channel at 1% depth or so to use the upward compression and pull a little bit of the more subliminal noise out of a mix.
Stardust had almost an identical purpose for me as OTT before I found OTT. It provides a way to take a channel of overly dynamic harsh or soft sounds, usually created after slicing up IronChefOfMusic ingredients, and gets everything into the same space. It doesn't have upward compression, but the multiband compression only really works well with an attack of at least five milliseconds, so the result is you will get highly boosted transients, but the rest will be will be smoothed out, which can create some uncannily weird sounds depending on what you put through it.
Granaliser by Morfiki? 👎
I used to really like the Granaliser plugin, the "morphing" options are extra neat, but it tended to be a bit crashy, it's only available as 32bit, and even though there's a "kids" version, I don't really want to talk about it.