I heard that you could change your name to something offensive so that jagex will change it to something else and then you could take that original name on your other account..
I'm not sure if this works or if this has ever worked.. I heard it on sythe many months ago. Don't try unless you're very desperate and are willing to be muted
This is false -
Account 2 ( with the good name ) --> (via pin)any name --> (via ANOTHER pin) any name
Note: It's going to take one month for you to change the name for Account 2 the second time.
Now you'll be able to set Account 1's name to the good name ( Account 2 ), remember to be quick!