Dipping Zombucks, Prospectors (non-Engelhard), or SB/SS?

[First Last]

So I have been getting some here and there...
If I were to dip this semi-premium bullion, just a second until the tarnish on the edges of some,
is a round no longer BU?

Non-proof.

 

[aussiesilver]

Bicarb soda, boiling water,aluminium foil and a dash of lemon or vinegar, all natural. Don't use commercial cleaning liquids

 

[swoydaz]

Once you’ve dipped, you’ve dipped.
If the coin was graded it would probably be noticed and commented upon.
Cleaning is sometimes very successful.
At other times a disaster.
I’d think twice.

 

[Gullintanni]

Bicarb soda, boiling water,aluminium foil and a dash of lemon or vinegar, all natural. Don't use commercial cleaning liquids

This is one of the commonly shared but WRONG old wives tales.
Vinegar alone or bicarb alone is fine but when you mix the 2 together you effectively remove both of the benefits.
The fizzing you get when you mix bicarb and vinegar is the reaction of the 2 cancelling out each other.
The bicarb loses its alkaline and the vinegar loses its acid.

 

[First Last]

Once you’ve dipped, you’ve dipped.
If the coin was graded it would probably be noticed and commented upon.
Cleaning is sometimes very successful.
At other times a disaster.
I’d think twice.

Not a coin, as mentioned... bullion rounds.

 

[Alloy]

I concur with @aussiesilver and @Gullintanni in the baking soda and aluminum foil method. Instead of vinegar, use a teaspoon of salt (assuming you use a tablespoon of baking soda).

I've refined the method a bit to use pure salt instead of standard table salt, which has added anti-caking agents and often iodine. Pure salt can be found as Canning and Pickling Salt. It's free of all additives (apparently anti-caking agents are undesirable for canning and pickling). In the US you can get Canning and Pickling salt at Walmart for $2.00 or less.

The aluminum foil is supposed to line a non-metallic bowl. If you go that route, I recommend heavy duty foil, which is cheap and easy to find at any Walmart or supermarket. Even simpler is to use small disposable aluminum foil food trays, like tart pans or meatloaf lunch pans. They're also cheap. I think I got 50 for $10 on Amazon. With these disposable pans, which you can reuse, there's no need for a separate bowl, so that reduces the part count by 1.