In my experience, there are no quiet MX switches other than silent reds and blacks due to the bottoming out and upstroke noise they all have. Sure, rubber o-rings can prevent a lot of bottoming out noise, but they dramatically reduce key travel, and you still have the upstroke noise. The proper solution for MX switches, in my view, is precisely what Cherry is doing with their "silent" switches: add rubber pads to the sliders themselves so that they self-dampen the noise they make. Everything else is a half-measure at best, even rubber clip-ons.
The one downside to these silent MX switches is that with all that noise gone, the "scratchy" noise from slider friction becomes much more noticeable. The only way to treat that is with a light lube, but that's all more trouble than it's worth to me.
That's why my favorite switch is Topre with silencing rings. There is no discernable slider friction to begin with, and no upstroke noise, so all you get is a very satisfying, soft thock, which is almost imperceptible in an office environment.
Oh, and with any keyboard there's stabilizer rattle which can only really be solved with thick lube, but at least you only need to apply the lube to a handful of spots.