Hello:
WOW...!!! What a Mess...!!!
Thinks happend you now...
I'can not know what you did it wrong...
But, how to fix, I can haelp you on that...
Put the part in a cup, a chipper one (Do not use the expencive czech cristal from your grand mom)...
And Spray the piece with oven clianer foam, the cold formula...
Here I use the "EASY-OFF Zebra" (cold formula) Brand, from Beckitt- Benckiser...
Please, test in a transparent sprue part FIRST...!!! To be sure...
My be necesary a couple (or more) of aplications... Do not desperate and let and allow the product to work...
Let me know, but I did it before with NO problems...
Diego
P/D: You can use remove painters from Mr. Hobby also...