This is a good question and I'll be interested to hear what others have to say.
Before we talk about detergents, from what I've read, it's important that the items be loaded in such a way that they don't touch each other as it is said that this can cause abrasion and damage. To avoid tarnishing, your sterling silver shouldn't touch other metals. It's also a good idea to let the items cool down completely before unloading the dishwasher for two reasons: they are apparently more prone to damage and chipping when they are hot and also I've heard that the gold trim that you mention can be rubbed off more easily or worn away more if handled or wiped when hot. They should also dry to a better finish if allowed to dry slowly in the machine with fewer water marks and spots than if removed soon after the cycle ends.
As for the detergent, this is an interesting one. Logic suggests to me that my Woolite of dishwasher detergents is to use an enzyme-containing liquid detergent such as Cascade Complete liquid/gel (dark-green bottle). This detergent has no bleach. I would expect it to dissolve quickly and clean a lightly-soiled load well using the delicate cycle at low temperatures. However in this scenario it may not remove tea/coffee stains. If that is a problem, use a chlorine-based liquid detergent such as Cascade Gel (light-green bottle) or Palmolive gel, or a pac containing oxygen bleach.
Using a rinse aid should also help to improve the appearance of the items (fewer water marks, spots etc.) and improve drying -- especially important as the delicate cycle's final rinse temperature is likely to be lower. The use of rinse aid is said to protect glassware against corrosion (etching) by not only neutralizing the alkalinity of the detergent but also by promoting better draining of the dishes leading to less residue on their surfaces. Apparently it is thought that etching actually occurs after rinsing during drying -- but with the cause being what has already happened during the wash and a lack of thorough rinsing. It's also recommended that you not rinse your dishes before loading the dishwasher -- they should go in dirty.
Does your machine have a built-in water softener, or do you have a whole-house softener, or do you live in a soft water area? If so, any detergent should leave dishes looking good. If not, you might have to use something like Cascade Platinum pacs to avoid horrible build ups of film, clouding, spots, white marks and streaks etc.
If you can, you may wish to start by experimenting with just one plate and one glass. Try leaving them in the dishwasher for several cycles along with your regular dishes and monitor their appearance to see if there is any change or effect. Any potential change should be obvious when that piece is compared to the rest of the set.
Fine china companies have an approved list of detergents. Surprisingly, they have typically suggested that customers use liquid detergents (containing chlorine bleach). Here's a typical list from Waterford.
Ensure your Waterford crystal remains pristine by following our care guide, including washing tips and storage recommendations to maintain its brilliance.
www.waterford.com
