casting soldiers

So I have been thinking of and experimenting with ways to get my soldiers into wax so that they can be cast. The first option I tried was putting then straight onto a wax tree and investing them straight but in the back of my mind I did wonder whether or not the plastic would effect the silver cast soldiers because in second year when I cast my little people the residue of the plastic left an ugly texture on the cast. Unfortunately both casts of my soldiers ahd the plastic residue left on them and therefore have porosity. Not to worry tho< beacuse i will use them in the right context and the porosity will stand a purpose. But for now I need to create alot of soldiers without porosity- so it is off to the cold silicone molds I go!