Test it first too make sure it is real silk.
Lots of these Indian pure 'silk' rugs are nothing of the sort and are in-fact a mixed wool mix.
If its a true 'silk on cotton' then it will be a high value, hypersensitive clean.In other words go carefully and charge the correct price for the privilege.Your starting price should be in the region of £110.00 for smaller sized up to £280.00 for larger silk rugs.
If this is not acceptable to the client then don't do it, this is a professional clean on a very expensive item, at your risk.
This is a definite LM clean only that should be carried out off site, you must not under any circumstances over wet.
Heavy pre-vacuum f & B, pre-spray with Micro-Splitter No 4 then either pad off or LM tool clean. Dress pile, dry and inspect,clean again if necessary.
Better to do two cleans than try to bang it out in one go.
Texatherm is another option that works very well.
If upon drying the pile feels brittle/stiff then you over wet it but don't worry just vacuum again then towel the top of the pile with a dry clean solution, it will soften up again and dress pile. Job Done