I do a lot of charity sewing too but I've always gotten good responses from people when I've mentioned it. The gals at work always want to see my projects and often want buy them, but when I say it's for charity, they understand.
I make a lot of blankets for a teen shelter. When I first started they told me not to make quilts, just simple blankets, 2 pieces of material sewed together, nothing fancy, the reason being they found that when the teens returned home often family members would take the quilts and sell them! They were turning up in ads or in garage sales! Yikes!