Ah, there you are!
Ian, I have found in my practice that it is difficult to teach Aikido without using some of the Aikido jargon. What I usually do is provide people with a dojo manual which includes definitions of terms and a brief overview of the underlying philosophy. Generally I recommend to all new students that they read Kissomaru Ueshiba's little book The Spirit of Aikido. This relieves me of the burden of "ramming" Aikido philosophy down their throat.
In my dojo we seem to have people of all religious and philosophical stripes. Everyone from witches to fundamental fire and brimstone Christians. Generally I tell people if they have a problem with "ki" and "oriental philosophy" that it is not the terms which are important, but how they practice and train their techniques. The Founder stated in one of his doka that he saw aikido not as a religion but as a physical expression of the highest in all religions - peace on earth.
As to how can you teach your students all of this? Well, first work on embodying the principles in your practice and in your daily life. Then your words and practice will mesh.
Too often I have run across persons in Aikido who mouth the philosophy but then proceed to behave in fairly brutish and selfish ways.
Then there are the others who only train the techniques and pretend the philosophy is not there. They perhaps feel that they are not "profound" enough or some such. For me this robs the students under them of possibilities for even greater understanding.
The path of Aiki is fairly clear, train the basics, practice techniques, study the writings of the Founder and others, practice, attend as many seminars as possible with as many different teachers as possible, practice, meditate on your understanding, practice ( do you notice a trend here?
In my take on teaching, the teacher is the least important person in the room. Every student I put up for any examination or for yudansha is a reflection of my teaching. Their positive achievements are theirs. Their mistakes are mine. This for me is the only honest standard for teachers in any field, but particulary in aikido.
As to adverising, some is good, however watch the pitfall of trying to make your self sound too good. We have a gentleman here in the states who always advertises himself as a student of a disciple of a aikido movie star. I am certain he is proud of this association. He runs a "successful" dojo. Many of his students may enrol thinking they will meet this movie star. The reality is much different.
Your best adveritising is always your students. Treat them with respect, provide them with consistent training, and keep your training/skills up to date, and, they will make certain that others enrol.
Hope this long-winded peroration helps
Yours In Aiki