Lemon juice won't remove silicones either. I've heard it said that baking soda will remove them, but no documented evidence that proves it definitively. Also, it may be natural, but it's more harsh than just using a shampoo. You would likely be better off to use a silicone free low poo (sulfate free shampoo) that contains Cocamidopropyl Betaine or Coco Betaine, or you can also use a sulfate shampoo to remove them.

Sally's has a good amount of CG friendly products. Just be sure to choose ones that are appropriate for your hair properties. Off the top of my head, these are all CG friendly: EcoStyler gels, Cure Care conditioner, the As I Am line, the CURLS line, GVP Conditioning Balm, and Volumax gels. They have a lot of other CG products too. There have been a few Sally's threads before, so try an advanced forum search to find more suggestions.

Ulta will be pricier, but they also carry some higher end lines like Devacurl and Carol's Daughter. I'd check online also, since you can often find discounts or free shipping deals. Aveyou.com, iherb.com, and Curlmart are all possible options.

Really the best thing you can do is be knowledgable about ingredients. Know how to recognize a sulfate or a silicone, and know how the various silicones work because they aren't all created equal. Beyond just water soluble (CG friendly) or not, there are some silicones that resist buildup and others that evaporate off the hair during the drying process. Also, read the ingredients list of a product you're interested in buying. Sometimes even veteran CGers will be surprised by a sudden ingredient change that they only noticed when a much loved product suddenly gunks up their hair.
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