Question:

As-salaamu ^alaykum,
I wanted to know about using as-siwak (miswak). I know it is sunnah, but are there any certain ways in which to use it to get more reward? Is the siwak to be washed after each use? Any advice is greatly appreciated.
Thank you in advance.
Answer:
Wa ^Alaykum As-Salam,

Yes there are ways and it has many benefits for Brushing Teeth Using Siwak (Tooth stick) among them:
1. Siwak cleans the teeth
2. It strengthens the gums
3. It reminds one of the Shahadah at death..
4. Multiplies the reward of the prayer to 70 times (as per the hadiths):
قال رسولُ الله صلى الله عليه وسلم :" السِّوَاكُ مطهرةٌ للفم مَرْضاةٌ للرّب " رواه أبو داود بإسناد قوي.
وقال :" ركعتان بِسواك أفضل من سبعين ركعة من غير سواك " (أخرجه الهيثمي في المجمع).

The best kind is called "Arak", it has a minty taste. It's recommended it to damp it with water first. It sould be used to brush teeth from right to left and back.  And to brush tongue and mouth top. It's Sunnah to use it before wudu', before praying, and before sleep and after waking up.

It's very rewardable if done sincerely for the sake of getting reward from Allah.