Pinterest Testing- will lettuce continue to grow?

I know a lot of things will sprout if you just put them in water, but could I really make lettuce regrow?  I saw several pins, including this one: http://www.pinterest.com/pin/394276142348903220/
that said it was possible.

Easy to do: just cut the stump of lettuce, put in 1/2 inch of water, check water daily.

At first, the lettuce did great.  It shot up quite quickly.  In one week my lettuce looked like this:

After one week, it's grown a couple of inches, and looking pretty!

I kept changing the water every day, but the growth slowed down a little, and after 2 weeks I decided it wasn't going to work, at least this time around.  After 2 1/2 weeks, I took the following pictures, and then threw the lettuce away.

The growth has not been too bad, but do you see the rot?

Changing the water every day didn't stop it from going rotten.

The rot was all the way through.  Yuk!

 I've seen the pictures, and am quite sure it can be done.  At first, it was working, but we are talking a few inches a week, at most!  Is it really worth the trouble to do this for a month or more, and hope it doesn't rot like mine did?  Not for me.

I can see in the summer, if I plant lettuce, to just cut off the top, and let it keep growing in the ground.  This was way too much trouble for rotten lettuce.  Won't try it again in just water.