Is it permitted for a divorced woman to immerse in a mikveh?

Good week,

It is forbidden for a divorced woman to immerse in a mikveh as long as she has not remarried (see Responsa of the Rivash, siman 425, cited in the Beit Yosef, Yoreh Deah, end of siman 183).

And it is written in the book Shulchan Yosef (pages 116-117), בשם הגר"ע יוסף זצ"ל, that there is a severe prohibition for single women, as well as divorced and widowed women and unmarried women, to immerse in a mikveh in any form whatsoever, so long as they have not married according to halacha. And since there are rabbis who send single women and the like to immerse for a segulah or for purity, it should be made known that there is no basis to these things, and there is no benefit in them, and it is a sin to cause mishaps and stumbling through this matter. The bath attendants must be careful, and warn others, not to permit single women and the like to immerse.
 
With blessing,

Hillel Meirs