Thanks for an interesting question.
According to the Global Forum for Sports and Environment,
http://www.g-forse.com/archive/news259_e.html, water does damage golf
"...So is a ball inferior, if it has been submerged in a body of
water? 'Yes' says an U.S. Army Research Laboratory study. Golf balls
absorb water that cannot be removed and this affects a permanent
change. Testing by Golf Digest in 1996 found a golf ball submerged in
water loses six yards after one week, 12 yards after three months and
15 yards after six months.
According to a former Spalding executive, Eddie Binder, the used-ball
business makes "more than $200 million in retail sales a year,"
compared to $750 million in the new ball business. A
Massachusetts-based company Performance Indicator, however, could be
about to upset the golf cart, by introducing a chemical into golf
balls that is activated after the ball has been in water for a period
of time, causing it to discolor, and making it impossible for
companies such as Nitro to recycle..."
Probable Golf Instruction also notes:
"...The covers of golf balls are pourous and will absorb water; this
changes the viscoelasticity of the cover and the golf ball will fly
significantly less far..."
So, I think that there is consensus and a study, as you desired, that
has shown that submersion can negatively affect golf ball performance.
I trust this answers the question.