I think one of the questions polygraphers supposedly like to ask their victims is if they know anything about polygraphy. If they respond that they have visited a website named "antipolygraph.org", are they likely to automatically fail the test?

anti-,

I think it is likely that mentioning that one has visited AntiPolygraph.org significantly increases the risk of:

1) being accused of deception and/or

2) being accused of using polygraph countermeasures.

A decade ago, I asked the American Polygraph Association (APA) how its members would handle those who admit to knowing about "the lie behind the lie detector" (that is, the lies and deceptions upon which polygraphy relies). Then APA president Skip Webb declined to provide a substantive answer:

https://antipolygraph.org/read.shtml#informed-subjects

The polygraph community has yet to publicly state how its members are to handle those who admit to an understanding of polygraph procedure.

Thus, for those facing a polygraph interrogation, I think it is safest to deny having researched polygraphy, and in particular, to deny having visited AntiPolygraph.org.

When polygraphers ask what an examinee knows about polygraphy, the kind of answer they find reassuring is something like, "My friend's father is a police officer, and he said to get a good night's sleep, relax, tell the truth, and you'll do fine."

Any indication that you understand the true function of probable-lie control questions, or possible countermeasures to the polygraph, is likely to put your polygraph examiner on guard and make him/her suspicious.