You don't need a clicker to clicker train. Clicker training is often times referred to as marker training. A marker can be just about anything as long as it's short, consistent and is followed by a treat or reward. I love clickers because I can move quickly, its a mechanical skill for me that I don't have to really think about, I just observe and react when I see what I want. My dog loves clicker training because she has learned how it works in a fun way.
If you don't have a clicker with you, don't use the clicker on time or click all the time without rewarding, a clicker is not for you. You can just as easily use a marker word such as "yes" or "good" followed by a tasty treat and your dog will just as quickly learn the behaviors that pay and those behaviors will start happening more often.