It sounds counter productive for the prevention of dehydration, as to why one would want to bring on the affects of an enema. By it’s very nature, an enema, without fluid replacement would hasten dehydration.

Now if the recommendation is, substituting seawater for some of the more common enema solutions, then yes, seawater would likely work, but so will soapy water.

If using seawater as a substitute of traditional enema solutions, just be sure an enema is medically necessary and adequate fluid replacement is available. Also, seawater is not/may not be a biologically clean solution. Vibrio cholerae is known to infect shellfish and can be cultured from seawater containing such shellfish.

Perhaps one of the physicians on the forum could comment.

Pete