(click image for larger view)

Here is something I did with a prop, though much the same sort of thing should also be possible with a figure. This isn't exactly an answer to the question you asked, but might be of use to someone. You can animate the Texture_Strength of a transparency map. With the dial set to zero the map has no effect. When the dial is set to one the transparency will work.

An advantage to this method is that you can make only part of a material transparent, and in theory at least, with a bit of ERC you should be able to make several materials (or parts there of) transparent. If you plug the transparency map into the Specular_Value, as well as the Transparency node, you can keep specularity working on the visible parts, whilst precluding specularity from transparent parts, but you must remember to set the Transparency_Falloff to zero.

In order not to have the transparency showing by default in the P6 screed preview, I had to use a bit of ERC to slave both the Transparency_Value and the Texture_Strength of the transparency map to a valueParm dial "Make_Hole". With this set up the transparency only showed when the image was rendered, not in preview. The relevant code in the pp2 was as follows:ProSpell Demo Version

           valueParm <span style="color:#00ff00;">Make_Hole
</span>                 {
                        name Make_Hole
                        initValue 0
                        hidden 0
                        forceLimits 0
                        min -100000
                        max 100000
                        trackingScale 0.004
                        keys
                                {
                                static  0
                                k  0  0
                                }
                        interpStyleLocked 0
                        }

                shaderNodeParm Preview_PoserSurface_7
                        {
                        name Preview_PoserSurface_7
                        initValue 0
                        hidden 1
                        forceLimits 1
                        min 0
                        max 1
                        trackingScale 0.01
                        keys
                                {
                                static  0
                                k  0  0
                                }
                        interpStyleLocked 0
<span style="color:#00ff00;">                  valueOpDeltaAdd
                                _NO_FIG_
                                ball_1
                                Make_Hole
                        deltaAddDelta 1.000000
</span>                 }
                shaderNodeParm Preview_Image_Map_12
                        {
                        name Preview_Image_Map_12
                        initValue 0
                        hidden 1
                        forceLimits 1
                        min 0
                        max 1
                        trackingScale 0.01
                        keys
                                {
                                static  0
                                k  0  0
                                }
                        interpStyleLocked 0
<span style="color:#00ff00;">                  valueOpDeltaAdd
                                _NO_FIG_
                                ball_1
                                Make_Hole
                        deltaAddDelta 1.000000
</span>                 }