Why not just multi log? Have you accounts ready to log into the world and hold Alt and hit Tab button to switch between the windows very quick so you can hit log in on both of them within seconds. Or just use a bot client and the runescape client to multi log. When you drop trade you run the risk of being intercepted which is rare but I did it back in the day for 13M.
If you attempt drop any large increments of GP it prompt you with a warning screen alerting you if you want to proceed. So of course you can drop trade since "free trade" was re-established.
Just multi log, have both windows up.. put em on the same world.. minimize them and click log in as fast as possible, you'll multi log.. it'll lag a lil tho
it was not working from December 10, 2007 up until December 21st, 2010. But yeah now it works but i wouldn't reccomended it, if you HAVE to do it make sure you find an empty world and go somewhere where ur sure no one is around.