I agree that using a bottle at this age is acceptable. It is comforting and it meets his needs. Children have a suck need. That is okay.
If the issue is control over mess, that is something you need to work on. Babies make messes. That is how they learn, they have sensory experiences, cause and effect, etc. When my children make a mess, they help clean it up. It teaches them to be responsible.
In addition, at 19 months he can drink out of straw. Here is a good link
http://www.mother-2-mother.com/cups-older.htm
Scroll down to How Can I Get My Baby to Drink from a Straw?
I use the take and toss cups for my kiddos, they are top rack dishwasher safe. My kids have been using them from 9+ months.