The phrase "added themselves" is correct and usable in written English.
It can be used when referring to individuals who have included or enrolled themselves in a group or activity.
Example: "The participants added themselves to the list for the workshop."
Alternatives: "included themselves" or "registered themselves".
Since then an additional 190,000 people have, through various means, added themselves to the Labour leadership electorate.
The bouncer let them pass, and they went upstairs to a ballroom where they added themselves to the Ming family wedding reception.
In the election, Romneys, Pryors, Doles, and Sununus added themselves to a political gene pool already awash in Tafts, Bayhs, Clintons, Udalls, Jacksons, and Chafees.
"Who else caught the disease at D.F.G.?" Within hours, 24 conference attendees from around the world added themselves to Mr. Zeifang's Facebook list; within a week, the number climbed to 80.
It happened at the end of the nineteenth century, with the Spanish-American War, when the Spanish empire finally collapsed, as Cuba and Puerto Rico added themselves to the trend among former colonies in the Americas by repudiating it and seeking independence (as did the Philippines).
Stunningly, the N.H.L. has no suspensions in the pipeline even though three of its series in a head-shot-filled first round are headed to a Game 7. New Jersey and Florida added themselves to that list when the Devils' Travis Zajac played overtime hero in Game 6, writes Sarah Kwak on SI.com.
The trifle also comes with a handy sachet of bacon pieces for customers to add themselves.
And this time CES exhibitors were adding themselves to the lineup in the week before the show, Oxman said.
"Lord of the Rings" took its time to assemble, with musicians adding themselves to a slowly enlarging picture.
And everyonewas doing the math while the buses gave them back,all the town's families adding themselves up.
So, they decided to add themselves to the highlight reel the only way they could manage, by hitting Kings in the head.
