Hi,
Met a saucer sized kids slime on cut pile pp yesterday. It was 12 months old and set like a rock. In honesty its one i wouldnt usually bother even trying to remove, but i had time and willingness to try.
1,2-Dichloroethylene softened it - must be careful with this stuff we use it to remove glue and it will delaminate - so keep it on the slime only, i used a towel poltice with no pressure for 2-3 mins.
This allows citrus gel from prochem to penetrate it and begin to break it down. Liberal application to surface with butter knife agitation.
Rinse with hot water a reapply citrus gel/agitation.
It started to come off in lumps of clear goop and after maybe half hr i had it all out apart from a faint trace of the red dye from the slime.
Its one i would never commit to getting out, even now i have as it takes too long on small job. We were in that house for hours yeaterday doing lots of work so it allowed me to work on it, leave it and go back to it.
1-2DCE can be bought from flooring suppliers - the specific one we used was styccoclean solvent. Good gear, saves petrol as you fly home
Hope this is of some use
Graeme