Dried DPM On Light Safety Floor

DPM'd a room in a school on Friday, barriered it off, the usual. Then came in today and some absolute candle has walked through the stuff and down a coridoor I've recently fitted in Safetread Universal Venus. Does anyone have any secret ideas how to get it out without damaging the floor. I've tried lightly scraping it with a flat exacto blade, meths and spirits eek: I know before anyone says anything, I'm desperate) and yelling at it furiously.

Any help would be appreciated, cheers

 

which dpm

 

Tremco ES100

 

tremco aw421 cleaner

 

I take it you are charging for extras?

 

Of course

Cheers mjfl will grab some tomorrow and see how we get on. Will post pics if I remember

 

Client wanted it all ripped up in the end even after I bought the cleaner that was recommended. Re-screeded and re-fitted was about 24 square in all. Ballache but they paid for the extra materials and labour.