not a teacher
That is an interesting question you are asking.
In Germany it is as follows:
host: male form of "hostess". A host/hostess is usually understood as a person who takes care of the visitors of a booth at a fair. Depending on the type of the fair they may dress very sexy - of course - to attract more customers to the booth. Edit: "Take care" is the wrong expression: They dress up in special clothing and stand near the booth (usually not inside) to attract people to come inside the booth where the more serious or knowdlegeable represaentatives of the company are.
However, if you book a hostess at an escort agency it may have the same connotation that you described, but not necessarily. Business men often just book them when their wife is absent for some reason.
A (TV show) host: the presenter of a show. Strangely we call it "moderator" in Germany and many many people think this is an English word.
P.S.: I googled if hostess in connection with fair has the same meaning in the US, but I couldn't come to a conclusion. Hopefully a native can help.
Note that hostess is derived from the latin "hospes"