TLIK: I don’t know the precise Lashon of that M”B, but a Gartel just means a belt.
I know there are Poskim who advise against. However Bimchilas K’vodam (and I do say this with as much trepidation as is possible but still say it), it cannot actually be Assur. It is M’vuar from the Gemara that it is untenable to say there is something wrong with it. I have brought this Ta’ana to Poskim and Roshei Yeshivah and every single one has said that claim here is not wrong. The only possible answer someone gave was that in the time of Chazal it wasn’t a Bizui for clothes to touch the ground but in 16th-19th century Europe it was (and the Dochak in that answer is obvious).