I have tested it from command window. This way:
->Open two tables (parent and child)
->Create a browse window to each of them.
->Set a relation between tables. This step you will see only related records on browse window of the child table. Ok.
->Destroy the relation between tables (set relation to command)
->The child window browse continues to show only the related records of the parent window. No matter what you do (refresh forms, goto recno(), etc.)

Sorry by later response. I was on vacation...