I (we) use Liquid Plumr every couple of months.  Our plumbing is pvc and quite a few years old but Plumr does not hurt the pipes.  I particularly like the 2in1 bronze/silver, gel. 

My idea/suggestion:  What would it take to include a "plunger" attached to the bottle?  I've seen the "snake" and although a great idea, I'm very doubtful that a 1/18" of flexible plastic will do much to snake a drain (which is why I've never bought it).  Just think of all the "single" women and men, apartment dwellers, and the like that could benefit from having a small, yet durable, plunger attached to the bottle.  I understand that the product is suppose to work without anything else, but sometimes the drain needs a little push (just like the snake idea).

Came out with a pre-measured packet with all you need in it like tide pods. This would be so easy to use and i wouldn't have to worry if i was using too little or too much.

I was all excited about the new Liquid-Plumr which included a 23" snake.  Wow, what a wonderful invention!   I unfolded the snake and the plastic broke where it was folded.   Figuring I may still have enough snake left,  I unfolded the next side and the plastic turned white and cracked  which meant the plastic was stressed and possibly going to break.  My suggestion is that instead of folding the snake into the packaging holder, it should be rolled into a circle and fastened to the large front of the bottle instead of to the side.  This would put less stress on the plastic and may save the snake.   I was afraid to use this snake in my already slow drain for fear it would break and add to my clog.  I love this product.  Please improve this packaging.