Like in "Polish jokes"?

Yes. I've actually never heard of making toast like that (was making a joke), but I'm quite sure that if it existed, we'd call it Polish toast.

As inappropriate (bigoted) as it is, the word "Polish" has been used in my area to label something as generally "backwards" or nonsensical. Or when there is some kind of clusterf#ck situation.

You can apply the adjective "Polish" to many things. I remember a notable occasion when my sister and I had spent some time in New Jersey. We complaint about typical, though innocuous, things that would confuse/irritate outsiders. For example, the fact that you cannot pump your own gas there, or strange aspects of the roads, like "jug-handles" (which require that you take a right in order to make a left). When we finally left New Jersey, my sister said, "Yes! We're finally out of this Polish state." It was funny and, yes, you had to be there.

I am well aware that this doesn't "excuse" bigoted terms, but: I have people of Polish descent in my family, and I have worked amongst Polish people (Polish-Americans) who just laugh at the usage.

"French" as a modifier, on the other hand, stereotypically conveys either something "dirty" or something done without proper "manners."