Spray the C-22 onto the lace and allow it time to ` work` ...allow it to soak in / on for around 15 minutes....it needs time to soften the residue...then rinse it out ..... you can try sourcing ` Autoglym` tar-remover [for cars !] at a car -accessory shop...you can soak the system in a bowl of it with no harm to the lace /hair..... leave it soak for an hour and then wash it out..... I suggest your issue was caused by them pressing the system onto glue which had not been allowed time to dry-in .... you have to allow at least 15 minutes, normally, between coats of glue and the final coat, before popping the system on, otherwise it will seep through like this and solidify onto the hair /lace...... hope that helps .....the C-22 should do the job..just allow it enough time to work.