A grooved runway is not dry - it's wet. This was put to bed years ago.
CAP789 ch11 5.3
"It is not sufficient for a runway to be considered, for performance purposes, as dry when it is wet solely on the basis that it is constructed with, for example, grooves or porous friction course pavement. Dry runway performance must only be used when the CAA has accepted in writing that the aeroplane can actually achieve the 'effectively dry' braking action referred to in the EU-OPS definition. However, there is currently no provision in the UK for notifying operators of runways having such surfaces."