Yeah, its where you press back. So essentially your inputs should be like:
(already grabbing ledge) back > up b > back > jump forward > forward b > whatever, but you have to do it all pretty fast (and btw I should mention, you dont HAVE to klaw on get up, but imo its easily his most versatile invincible get up due to the fact that it allows the most options afterwards AND is non-interruptable). Its actually not too hard to do once you get it down, but it takes a bit of muscle memory.
And as for speed hugging, I usually just short hop > fast fall. Pretty sure up b and sliding off to the ledge is faster, but its pretty unsafe cuz if you mess it up or are too slow you die, and besides, you usually dont want to be around the ledge area when characters are right next to it due to your huge hurtbox, bad horizontal recovery, lack of aerial options that you wont die from while walking off the ledge and using immediately, etc. So basically the tl;dr is its usually unsafe to try and speed hug with Bowser with anything slower than short hop > fast fall anyway, so why try and use a riskier option when you have a safer option. Plus, Bowser actually has surprisingly decent options to prevent ledge play with Fair, Klaw, Dtilt, Ftilt, Fsmash, and even Firebreath lol, so I dont really like taking risks at the ledge personally.