"- La cloche! cried gleeful Lenehan. Trained by owner. No sawdust there." (U11.415)
Sawdust, as I learned from the Police Gazette (1880), was used to make paddings called 'symmetries'. They were worn mostly by stage performers, both female (legs) and male (shoulder and thighs), to enhance their figure. The smacking sound of Miss Douce's garter against her thigh is evidence that there is No sawdust there.