I read online that chloroform is lethal so wouldn't it be easier to drink the whole thing?
I have no idea if chloroform is lethal by drinking it. I only know about it's "knock out" capabilities, and not from any personal experience, either. But, I have seen the recipe online. Whether it's a "good" recipe, I have no idea. Your question asked how to knock yourself out, so I used chloroform in that context only.
And TBH, I've never much been one for the "poisoning" type of methods, as I'm well aware that the body will do everything it can to expel the poison, so there are many other preparations that need to be done to even make most poisonings feasible. I just think there are simpler and more effective ways to CTB. But, that's just my personal take on it. To each, their own.