I used a heat gun and a scrapper to remove 10 years of cetrol buildup from the caprails of the boat a couple of years ago. I followed up with a sanding
with 80 grit sandpaper and then 220 grit and the wood looked like new. Not sure if I would use the heat gun on the seams of the deck
though unless you were going to recaulk. My cockpit
seats were also treated with cetrol and had caulking and I treated them the same way, but I planned to recaulk them anyway so no big deal about the heat gun. I redid them with semco oil
since the cetrol(even without the gloss) left the seats a little too slick. The caprails were redone with cetrol natural which looks much better than the brown stuff or the orange. One thing I did learn which is not clear from reading the instructions on the cetrol is that the gloss applied over the coating results in much better UV protection than just the standard coatings alone. Never did think that would be true, but now I just apply a annual maintenace coating once a year with the gloss.