When I'm in doubt about the accuracy of the data about a food I find on My P.L.A.N., I double check it on the USDA searchable database. It is constantly being updated as new information becomes available. It shows 100g of coconut oil as having 0.00g of water.

Like yours, my search for coconut oil on My P.L.A.N. database shows 85g of water per 100g of oil. That doesn't even make sense, IMO, and may have been a data entry error, or something similar. It clearly has been updated on the current USDA database.

In situations like this, I just use the information from the USDA site to enter the item as a Custom Food.