1) Yes you can use olive oil to dot the petition and to dress the candle for blessing, but you should pray over it before you use it.
2) Here are three ways to learn --
A) See this web page i wrote on disposing of ritual remains
Laying Down Tricks and Disposing of Ritual Remains in the Hoodoo Tradition
https://luckymojo.com/layingtricks.html
B) See this forum thread on the topic, with questions and answers:
Disposal of Ritual Remains Questions and Answers
disposal-of-ritual-remains-questions-an ... 10676.html
C) Finally, this inexpensive book will help you greatly, now and in the future, with this and many other aspects of candle magic:
BOO-GRI-AHCM
The Art of Hoodoo Candle Magic by catherine yronwode and Mikhail Strabo
$9.00
* Choosing Your Lights: Lamps, Offertories, Jumbos, Figurals, Votives, Vigils
* Altar Layouts and Spell Timing for Lamp and Candle Spells
* How to Read Divination Signs from Candles
* Candle Spells to Draw Love, Sex, Money, and Success
* Candle Spells for Blessing and Protection
* Candle Spells for Reversing, Cursing, Break-Ups, and Hot-Footing
* Private Candle Service Manual for Use in Candle Ministries
* Public Candle Service Manual for Use in Spiritualist Churches
The Art of Hoodoo Candle Magic in Rootwork, Conjure, and Spiritual Church Services
by catherine yronwode and Mikhail Strabo
96 pages, $9.00 (Missionary Independent Spiritual Church)
disposal-of-ritual-remains-questions-an ... 10676.html