NO and NO.
Silicon is an element and does not smell of formic acid.
Silicone sealants are often formulated with Methyltriacetoxysilane as a cross-linker which releases acetic acid, CH3COOH, during curing.
The mask started off as a liquid that reacted to give a cross-linked solid. Now you have a solid you can not modify the shape.
This is not always true. The silicone rubber could be partially cross-linked. With heat and pressure it may retain a different shape. It should no melt to a liquid.