Ask Mr. Smarty Plants

You have raised some good questions that many suffers have wanted to know. How long does the nasty allergy inducing urushiol oil from poison ivy, poison oak and poison sumac last? How is it transferred? Unfortunately there isn't a definitive answer about how long the oil is contagious - some say the oil is potent for months to even years later. 
The Cleveland Clinic has a good online article about dealing with urushiol from these poisonous plants on their website. Here is some of their information:

Poison ivy, poison oak, and poison sumac are plants that contain an irritating, oily sap called urushiol. Urushiol triggers an allergic reaction when it comes into contact with the skin, resulting in an itchy rash that can appear within hours of exposure or three to five days later. A person can be exposed to urushiol directly or by touching objects—such as gardening tools, camping equipment, and even a pet’s fur—that have come into contact with the sap of one of the poisonous plants.
Urushiol is found in all parts of the plants—including the leaves, stems, and roots—even when the plants are dead. Urushiol is absorbed quickly into the skin. It also can be inhaled if the poison plants are burned. The smoke might expose not only the skin to the chemical but also the nasal passages, throat, and lungs. Inhaled urushiol can cause a very serious allergic reaction. Urushiol is easily transferred from one object to another, so clothing or tools that touch the plants, or pets that rub against them, can pick up the plant oil and pass it to a person.

Now to answer your question, unless you wore your wedding boots/shoes and dress into the wilds and connected with more poison oak or didn't wash before you put them on, they are most likely not contaminated with urushiol. It is only the clothing and shoes that you wore during the initial exposure that you should be concerned about decontaminating. Urushiol is fairly quickly absorbed into the skin and doesn't transfer.

The Mayo clinic has some advice about cleaning contaminated skin and objects. They also indicate that urushiol can remain potent for years on inanimate objects. Their advice: 
Wash your skin
Gently washing off the harmful resin from your skin, using any type of soap, within five to 10 minutes after exposure may help avert a reaction. After an hour or so, however, the urushiol has usually penetrated the skin, and washing won't necessarily prevent a reaction, but it may help reduce its severity. Be sure to wash under your fingernails too.
Clean contaminated objects
Wearing long pants, socks, shoes and gloves will help protect your skin, but be sure to wash your clothing promptly with detergent — ideally in a washing machine — if you think you've come into contact with poison ivy. Handle contaminated clothes carefully so that you don't transfer the urushiol to furniture, rugs or appliances.
In addition, wash any other contaminated items — such as outdoor gear, garden tools, jewelry, shoes and even shoelaces — as soon as possible. Urushiol can remain potent for years. So if you put away a contaminated jacket without washing it and take it out a year later, the oil on the jacket may still cause a reaction.

Below are links to the plant culprits if you would like to find out more information about these allergy inducing pests.

Pacific poison oak

Atlantic poison oak

Eastern poison ivy

Poison sumac