Curious as to what people consider the most severe/painful CP implement?

From my experience I would rank it close between a genuine Lochgelly Tawse and a little thing we got years ago from the Church of Sinvention in Canada called a Liquid Truncheon. Canes are wicked but these two....OUCH!

The tawse is an Ebay purchase from a UK antiques store. Marked J Dick XH" (for extra heavy) Incredibly dense, hard leather it's two tails are about 3/8" thick by about 3/4" wide and it's about 25" over all

The truncheon is a dense neoprene tube about 20" long and about 1/2" in diameter. (Think a hose but with a solid core) Quite stiff but still flexible enough that the end droops about 45 degrees when you hold it out straight. Even a casual flick cause deep throbbing pain.

When either of these two came out I used to become immediately amiable to nearly any other option she might offer.

What do you dread seeing come out? Or for Dommes....What makes your subs cringe?

I should note I've never experience single tails

A large Lexan paddle with holes.

I agree that the stuff made out of synthetics can be quite severe.
We have a delrin cane from Cane-iac that I find very hard to take. It's very dense and gives a deep throbbing sort of pain that lasts longer compared to the quick, searing burn of a rattan cane.

Two of my most intense ever, Ive been hit with a softball bat and a ping pong paddle.

Both landed in such a way to blur my vision and cause shortness of breath. The angle the bat came in was dull and thuddy pain. The paddle was a mix of thud and sharp stingy. Both of these incapacitated me for a short time with recovery in about 15 minutes.

Edit: for some reason i read this as cbt implements and not CP implements.

Brain freeze on my end. Cant get spanked with a softball bat