As human beings we are very prone to falling under the spell of pretty sayings without understanding what types of messages we give ourselves.  To illustrate, consider the following popular saying;

Inhale Love

Exhale Hate

There are many variations on the above, e.g.,

Inhale Love

Exhale Anger

Or Exhale Negativity. 

While these affirmations may sound good at a surface level and likely originated in order to help people, there are unintended consequences that make them ineffective statements.

The difficulty arises because of the way memory and our bodies react to messages.  There is a process called state dependent memory.  To understand this process, think of a time when you heard a song that you had not heard for a while.  Sometimes, we have associated memories with the song.  It can also work with smells.  We might catch a scent that triggers a host of memories.  The external cue (song, smell, etc.) triggers a state which has associated memories.  The same is true of feelings and thoughts and physical processes.  If we have been dumped on, it tends to remind of us of other times we have been dumped on.  Many of these state dependent processes occur beneath the level of conscious awareness at the unconscious level.  The later often having some unintended results which often get in the way of us being at peace with ourselves and the world.

How this applies to those statements is that when we use negative associations, it reminds us of other negative associations.  Exhaling hate, only reminds of us hate, which in turn has a negative effect on our being.  It is a self-defeating statement which focuses on the negative.

A better way to go about is to say something like:

Inhale Love

Exhale Love to Others

The second statement then becomes a positive statements thereby changing the whole tone of experience.  You are encouraged to make up your own second statements that suit your own personality and way of being.  Just try to ensure that they are positive in nature.