The "even if" bit from your link is helpful to consider.

Kettle logic:

1. I wasn't there.

2. I was there but had no motive.

3. I was there, had motive, but had no means.

Argument in the alternative:

1. I wasn't there.

2. Even if I was there, I had no motive.

3. Even if I was there and had motive, I had no means.

The first makes three conflicting statements. The second makes 3 consecutive arguments: I have an alibi, but if you don't believe my alibi, I still had no motive, and if you don't believe my alibi and that I lacked motive, I had no means.

I think it's even better if the burden of proof is placed on the prosecution (as it should be):

1. The prosecution must prove I returned the kettle in a damaged state (they can't).

2. They must prove I received the kettle in an undamaged state (they can't).

3. They must prove I received the kettle at all (they can't).

I think the difference is that in Kettle Logic the presenter knows the truth, and the truth doesn't match any of the inconsistent affirmatives ... or else it mostly matches one of them but the presenter believes it's easier for the audience to swallow one of the other, false, alternatives.

Perhaps, but this also implies that the presenter isn't just full of shit (or biased!). Sad fact is, people have attached truth to subjectivity in society as of late, and so one persons truth may not be another's even though both are wrong. Or right. Or a mix of both.

A good example of this is those rarer occasions when someone is accused of rape that never happened; and social media gets wind of it. To everyone who hears of it, mostly at least; the accuser is the honest one. And in some rare occasions, we find out they were not.

I know this specific examples happens, because it was how my mother was born.

The difference is that the kettle argument is simultaneous making multiple claims which are mutually inconsistent, and thus a kettle argument is by definition invalid. Even if it's true that any one of the kettle subarguments being true would achieve the desired goal of the overall argument (e.g. exonerating the accused person), the fact that all subarguments are being claimed simultaneously means that at the bare minimum we know the person is lying.

Of course, the "argument in the alternative" is only different by a slight technicality: you just put an "and even if I were lying in the previous step, ..." between each subargument.

Seems as though Argument in the alternative focusses on eliminating possible explanations. Kettle Logic involves claiming 2 or more explanations to be true while being incompatible with each other, making it a logical fallacy.