Google Teak water damage repair & site called ehow.com sounds like any novice can fix it! They make teak furniture & have to seal it for outdoor use with linseed oil (I think that was it) but it didn't look that great, maybe he didn't seal it enough. So hope this helps!

" linseed oil"

Boiled linseed oil (AKA 'BLO') hopefully.

Linseed oil takes years to dry, the boiled stuff is faster, but takes many thin layers.

'Once a day for a week, once a week for a month, once a month for a year, once a year forever.'

Either tends to create a very dark surface (nearly black in some cases) as they cure by oxidation and polymerization.