Effective ... as in ... it'll help me get over H? It'll get his attention and perhaps nudge him to want to work things out later? It'll pi$s him off? All of the above?
"Effective" as in it very often re-attracts the walkaway spouse. JEALOUSY 'WORKS', even if only in the short-term. You STILL have to decide if dating while still married fits within your own moral framework, and then you'd STILL have the same dysfunctional relationship (and H with all of his issues), but it DOES draw them back. Especially spouses with a strong jealousy streak.