I guess there’s a way to take vintage photos by applying a dab of vaseline on your expensive DSLR lens. Of course, this could be a great option if you simply suck at Photoshop.
And yes, it should be fine so long as you put a clear lens filter on your DSLR camera before trying this hack.
With a cell phone camera (or one you’re not worried about damaging) you can try putting Vaseline directly on the edges of your lens to give your photos an out of focus vignette just like old film cameras.
If you’ve got nice equipment, you should probably put your grease of choice on a clear lens filter that you aren’t worried about damaging.