Ok my fault-too mean to buy the right tool to remove the dead ISIS b/b from my Io so thought I'd have a go tapping the indents with screwdriver,molegrips etc..you get the picture. Sooo eventually got non-drive side out-drive side appears to be welded in + not much exposed alloy cup I can get at-getting bit worried if can't the thing out the frame's junked. How about riding the ****er with only the drive side cup in for a few miles? Is that likely to loosen it-any other ideas?
You have remembered one side is a reverse thread? Heat and penetrating fluid I doubt riding with only one cup in will losen it
just use the proper tool. even if it's seized you can cut alloy ones out OK
Don't know what tool you're using. For stuck squretapers i usually put a crank bolt through a penny washer and use this to hold the tool in place. Then get a long spanner and stand on it, that'll usually loosen it. For isis just use an penny washer at either end and a QR.
Err didn't actually use a tool at all 
,ISIS bbs have such a poor rep + have Shimano on all the other bikes so didn't want to splash out for a tool I'd only ever use once.Just tapped the wee indentations round with screwdriver/rubber hammer,lots WD40 + big pair molegrips gripping the exposed bit of the cup.Worked ok on the other side but drive-side seriously chewed + worried running out of metal to get some purchase on. ( and yes-drive side reverse threaded so un-screwing is clock-wise)