Dr Vonkler's Cup of Wonders

Dr Vonkler's Cup of Wonders, manufactured by Dr Vonkler, is a small pewter decanter that allows the user to 'cleanse their innards' via vomiting.

Discovery

Before the 'Cup of Wonders' was widely available, the laboritorea of Dr Vonkler discovered an unknown substance that could induce vomiting and flushing of the bowels when consumed, without wearing off the substance.
In this manner, a pill was developed that could be taken with a beverage of choice and retrieved once it had passed through the digestive system, allowing it to be used indefinitely.
Recognising the appeal such a product might have towards people riddled with indigestion, the product was quickly put to marked, but failed to succeed in communities that were not drawn to the idea of inspecting their stool regularly, followed by a the unpleasant and squelchy act of recuperating the product.
Instead, these cups were made such that, due to their infusion of the substance, they would enrich any drink allowed to decant in it with the wondrous substance in a much more subtle and hygienic fashion.

Availability

Most chemists stock a small selection of such cups, since they are popular but many households already own one.
Like many Dr Vonkler products there are a range of different variations to suit different price ranges, and cheap versions can be found in most households.

Utility

Although the primary use is medical in nature, it has gained popularity among practical jokers and people wishing to embarrass another, meaning that any wise person will customarily clink their cups with their guests and listen for that signature ring,

Manufacturing

Although the precise process is not publicly known, any skilled metalworker should be able to tell the rough composition of the metal and the process used in manufacturing the cups.
Unlike regular pewter, the alloy appears to contain a greater amount of Plomboidium then usual, allowing for a clearer, brighter 'ringing' when the cup is hit.
More expensive variants seem to have a higher amount of tin and seem sturdier and less blemishable.
The more expensive models are spun, or even hand-made for a more refined appearance.
Cheaper models are cast or even bent from punched sheets, resulting in an ugly seam along the back of the cup.
It is unclear at what point the unknown substance is added and whether the hightened Plomboidium has any influence on it's effectiveness. Just before polishing and washing the final product, the illuminated phrase "Authentic Dr Vonkler's Cup of Wonders" is embossed either on the side or on the base of the cup.