What can be used for 3d mods instead of epoxy sculpt?

I am going to start my first 3D mouth modification, but it’s really hard to get some epoxy sculpt or any other epoxy clay in my area. So, is there any other stuff, that I can use for this purpose, that is not epoxy? Yea, I can order epoxy clay itself, but delivery will take forever. It is not a big problem since everything I order delivers just like that, but I am just curious, if I can use something else. In the end, I just need something that I can sculpt with to make a small piece of tongue and teeth and then put it in the hole on DD head and attach it with this thing that I don’t know how to call, which is usually used to attach eyes. Since I don’t need to change the shape of head itself by adding some epoxy, it could be everything if it used just for the mouth piece? Is it? I am bad in chemistry, but I am sure that not all the materials are compatible to each other. I just afraid that something can stain on head, not only dyes, but some compositional parts of the material, if it stays in contact with vinyl for a long time. The easiest to find for me are fimo, la doll and some other self-hardening clays that papier-mache based. I am afraid that the first one will leave some stains on vinyl, especially before baking, when it’s raw, and that the papier-mache based clays will be not suitable for some reason, I don’t know why. I’ve just never dealt with them. What do you think?

If you are just making a mouth piece for an open mouth mod and not sculpting directly onto the head then you can use other clays.  I’ve never done a mouth mod myself but a friend of mine has and she just used air dry clay.  
La Doll clay should work fine, people sculpt entire dolls out of La Doll so I’m sure using it for a mouth mod will be fine.  Polymer clays I’m not sure, especially when it comes to bad reactions with the vinyl.  It should be fine as long as you don’t leave the unbaked clay in contact with the head for an extended period of time.

As for staining I would use white clay then paint and seal it afterwards.  It’s not uncommon for clays to transfer colors so it’s safer to just use white

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I’ve never done a mouth mod myself but a friend of mine has and she just used air dry clay.  
La Doll clay should work fine, people sculpt entire dolls out of La Doll so I’m sure using it for a mouth mod will be fine.

Thank you, seems like la doll is the best option for me.

Sounds like your mouth piece will be removable, polymer clay should be fine too. I would just opt for white, translucent, or that pinkish Super Sculpt color, rather than sculpting directly in a red colored clay--red polymer clays are usually highly pigmented and will even stain your hands for a while aftet working with them, so if you need to push the clay onto the head to shape it I wouldn't risk it.

All polymer clays have been safe after baking in my experience, however. The stain risk would only be in unbaked clay.