The deal will see the Philippines first-choice custodian move to Alexandra Stadium until January 1 next year, pending clearance from the Football Association, Premier League and Football League.
The English-Filipino former Chelsea academy graduate has not made a single Premier League apppearance since joining the Cottagers in 2006, although he made his debut in the 2011/12 Europa League campaign against Odense Boldklub.
It is not surprising then that Dutchman Jol wants Etheridge to seek more regular playing time, with first-choice Marten Stekelenburg and deputy David Stockdale ahead of him in the pecking order.
"Neil is one of the keepers who I think should go on loan and get 50-75 games under his belt because he's talented," Jol told Fulham's official website.
"Etheridge hasn't got the experience yet. He's played one match for us. He has never played in the Premier League and I think goalkeepers are living by experience."
Etheridge revealed in an interview with his new club that he hopes to "put a smile" on his Philippines countrymen in light of the recent typhoon disaster, and is also looking forward to their next match.
Crewe, who are 22nd out of 24 teams, host Port Vale in a derby game on Saturday and Etheridge is expected to make his debut.
"First game this weekend is a massive one and I hope I can be a part of us turning things around," he tweeted on Friday.
Etheridge turned out for the England Under-16s at youth level before going on to make his senior debut for Philippines in 2008. He earned his 40th cap against Hong Kong earlier this year and has established himself as the Azkals' number one.