I've also started keeping extra "o" rings and pin seals for the Excal battery pod as this seems to be a very susceptible area. I'm making it a habit now to change the seals as soon as I see them "setting" or starting to wear. This area has caused me more problems in the filed then anything else as I water hunt a lot.
The Excalibur is easy to take care of as it is water proof.
When possible, I do a fast rinse off at the beach. Be sure to remove the protective coil cover to remove all sand between the bottom of the coil and this skid plate.
As soon as I get home, I do a more thorough rinse off. If you have been shallow water hunting / diving It is important to remove the lower shaft so that you can flush out the inside to prevent salt and sand/grit from building up. Use a light soap solution weekly. The easiest way to do this is to take the detector into the shower with you, especially if you have a hand shower head attachment.
Caution: Be careful not to spray anything on the detector such as WD40 or any petroleum product which could damage the O ring seals, especially around the knobs or anything which could damage/soften the cables to the coil or head sets.
I have read that silicon spray can damage plastic - so you have to be careful with it also.
You also need to maintain the battery pod: The pin's to the ikelite connector under the flat rubber pin seal need to periodically cleaned to prevent salt/corrosion from building up and silicone crease put under the rubber seal to prevent detector from chattering.
Hopefully, some of the T Net members know what sprays to use and especially how to protect/dress the cables to keep them from cracking/drying out and will post their reply(s).
My Excal also has it's own room, and bed, and each night I tuck it in I tell it a treasure filled bedtime stor.....wait a minute.....am I telling too much?