There's this easy and trendy way, just keep an egg over your head and affirm about removing the curse, then break this egg by throwing it against a wall.
Also, if you somehow know the person who cursed you, then throw the egg on their photo or something, affirming about returning the curse. (Well it's optional)
I don't think there is any such thing as a "safe curse". While your intentions are appearing to be wanting to resolve a situation by placing a curse, regardless of its length, its still a curse. The individual you place it on will still be effected by it emotionally, physically and mentally. That alone, even if it is short lived, can still have devastating effects on ones own mental stability.
While I can humor your request as being thoughtful, since you are not looking to cause major harm, it is not possible to really understand the reactions of your curse until they play out. Some people may come out unscathed while others can be completely destroyed.
The safest way would be to not place a curse at all. There are other ways to remedy your situation, especially if this is an enemy of yours, I would try to reverse that and look into Honey Jar spells. Since I don't know the perimeters of your given situation that may not work either, but I would stress looking at a different means, besides a curse.
theres many ways to remove a curse, easiest is to have a sea salt bath. most can be removed rather easily, the problem is the majority of curses are overthought and most think they're doomed when in reality, most are cast because someone was mad and didn't watch their tongue [you might of cursed someone on accident, ever been cut off and glared at the person while thinking 'rude, i hope you get a ticket'? that can be enough to cast a curse] regular grounding and shielding can keep most negative energy away, as well as burning sage can cleanse away any lingering energy. if you were given an object and noticed the negative energy, cleanse the object and it should stop.