What is the best shampoo for EtG?

Excuse me, but I must inquire about the specific shampoo you've mentioned for EtG. Could you elaborate on what EtG is, and why one would need a specialized shampoo for it? Is it a common issue among haircare enthusiasts, or is it a specific concern for a certain group of people? Moreover, are there any notable brands or formulations that are widely regarded as the most effective for this purpose? Lastly, could you perhaps offer any insights into the science behind why this particular shampoo would be best suited for EtG? Thank you for your time and consideration.