LCLF says a baking soda cleanse is preferred over a sulfate shampoo to remove silicone buildup, but I've never found anything definitive that says baking soda clarification will remove cones. I think I'd choose the safe /proven route and use a low poo with Cocamidopropyl Betaine, since that ingredient is known to remove silicones.
CG since 11/2011
2c /3a F /Mii, low porosity

Fall Products /Routine:
Clarifying: Herbal Essences Tealightfully Clean
Low Poo: Renpure Luxurious Argan Oil
CO: Suave Naturals Tropical Coconut or Daily Clarifying, V05 Strawberry or Kiwi Lime
Tresemme Perfectly (un)Done, Cure Care, V05 Kiwi Lime Squeeze, V05 Strawberry, Renpure Brazilian Keratin (old formula),
PT: IAGirl's as needed