From Ukrainian it gets turned into "shch". Which IMO sounds about right. Mainly because sh and ch are shorter sounds in English (ch can also be a little hard), but shch gets the point across.
This was also the historical Russian educated pronunciation; it only changed by the end of the 19th century.
Speaking as a Russian, I think that "shch" is close enough for an international conlang. It's not a sound that's particularly easy to learn or explain.
