solo in a raid question

[Tigermeat]

Lots of the posts here talk about soloing raid bosses, but I dont understand how you do that because you have to be in a raid group to enter a raid. If you have someone join your group, convert it to a raid, and then enter, that person effectively cant "play the game" because they cant progress quests while in a raid group.

Is there any other way around this? If the person in your group leaves the group after you go in will you get hearthed out?

[Belloc]

Log on an alt and have a friend invite you to a raid. Log on your main and have them invite you to that raid and make you the leader.

Now you've got an offline member in the raid and your friend can leave without hearthing you.