The desguise factor, while having nominal appearance and effect no matter what you do, the fact that if a two hander always hits a slice with one hand, versus the topspin with two, this would indeed be a cue that opponents would start to recognize.
Using two hands on the slice and the topspin certainly would minimize this revelation.
That said, the effectiveness of the drop shot is the key. If you have better touch, can hit a drop shot with better control of the depth, the softness, the spin, and most important, the consistency, then you should look to what ever technique works within those parameters.
One thing for many two-handers, the ability to keep the plane the same within the stroke, (slice, flat or top), is usally increased through the stability of two hands. On the other hand, the touch and finesse of one hand is usually better for many.
There are exceptions across the board.
Dave Smith: Author, Tennis Mastery/Coaching Mastery;
Senior Editor, TennisOne; Dunlop Master Professional