Re: This may offend some of you but...
You know when you've burnt your shisha. When you inhale it burns - like, "oh my, I can't stop coughing" burn. It also tastes horrible. If the flavor is good, but you're getting the tickle, try packing a bit more of the Nakhla in your bowl and adding one half or one whole extra coal than you have before. Sometimes when it tickles it means you need to add some heat, and Nakhla is one of those tobaccos that is very heat tolerant.