Will the bubbles in Alka Seltzer plus clean my retainer like the fizzy bubbles in Poli-Dent?
You are talking about two totally different products.
The ingredients in Alka Seltzer Plus are:
Active Ingredients: (in each tablet): Acetaminophen (250 mg) (Pain reliever/fever reducer), Chlorpheniramine Maleate (2mg) (Antihistamine), Phenylephrine HCl (5 mg) (Nasal decongestant)
Inactive Ingredients: Acesulfame Potassium, Aspartame (Sweetener), Citric Acid, FD&C Red 40 Aluminum Lake, Flavor, Fumaric Acid, Glyceryl Behenate, Sodium Bicarbonate, Sodium Saccharin, Sorbitol
Do any of these ingredients kill germs or clean anything? The answer is No.
Just for the record, it's better to clean your retainer with a retainer cleaning product, not a denture cleaning product.