Everything under the hood is sealed with weatherpack connectors... there SHOULDNT be any issue with water intrusion into anything electrical...
Ive been using hoses and pressure washers under hoods for a long time including on such cars as my 96 Corvette LT4 with the dreaded optispark which supposedly can be killed by getting it wet at all... meh...
If you keep up with it monthly or every other month, it will stay mostly clean and you wont have to get real crazy with it if you wait 4-5 years...