The present invention relates to an auxiliary composition in particulate form for the laundering or treatment of fabrics, the auxiliary composition comprises a co-particulate admix of: (i) clay; and (ii) silicone; and (iii) optionally, a charged polymeric fabric-softening boosting component; and (iv) optionally one or more adjunct components; wherein the auxiliary composition has a Flowability Index (FI) of from 0.5 to 21, wherein FI=P.times.R, wherein P=the weight average primary particle size of the clay expressed in micrometers, and R=the weight ratio of silicone to clay.